National Advisory Committee for Aeronautics (NACA) - 36 Matching Results

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The 1350 F stress-rupture properties of two wrought alloys and three cast alloys

Description: From Summary: "These properties compare favorably with those of the strongest similar alloys previously investigated. However, compared with a 60Cr-25Fe-15Mo alloy, the three cobalt-chronium-nickel cast alloys are inferior. A correlation of NACA and OSRD (Project NRC-8) data is presented, showing the variation of rupture strengths with temperature in the range of 1350^o to 2000^o for alloys."
Date: November 1947
Creator: Reynolds, E E; Freeman, J W & White, A E
Partner: UNT Libraries Government Documents Department

Aerodynamic characteristics at subcritical and supercritical Mach numbers of two airfoil sections having sharp leading edges and extreme rearward positions of maximum thickness

Description: From Introduction: "A 12-percent-chord-thick wedge section and a reversed NACA 0012 section were chosen for these tests as they are representative of sections having no boat tailing and appreciable boat tailing (i.e., blunt and rounded trailing edges, respectively), and the results of this investigation are compared with those obtained from a previous investigation of the NACA 0012 section. Conclusions are drawn regarding the relative merits of the two unconventional sections and the conventional section in transonic speed range."
Date: November 6, 1947
Creator: Eggers, A J , Jr
Partner: UNT Libraries Government Documents Department

Aerodynamic Characteristics of a Number of Modified NACA Four-Digit-Series Airfoil Sections

Description: Theoretical pressure distributions and measured lift, drag, and pitching moment characteristics at three values of Reynolds number are presented for a group of NACA four-digit-series airfoil sections modified for high-speed applications. The effectiveness of flaps applied to these airfoils and the effect of standard leading-edge roughness were also investigated at one value of Reynolds number. Results are also presented of tests of three conventional NACA four-digit-series airfoil sections.
Date: November 14, 1947
Creator: Loftin, Laurence K., Jr. & Cohen, Kenneth G.
Partner: UNT Libraries Government Documents Department

Analysis of effect of basic design variables on subsonic axial-flow-compressor performance

Description: From Summary: "A blade-element theory for axial-flow compressors has been developed and applied to the analysis of the effects of basic design variables such as Mach number, blade loading, and velocity distribution on compressor performance. The relations among several efficiencies useful in compressor design are derived and discussed. The possible gains in useful operating range obtainable by the use of adjustable stator blades are discussed and a rapid approximate method of calculating blade-angle resettings is shown by an example."
Date: November 26, 1947
Creator: Sinnette, John T , Jr
Partner: UNT Libraries Government Documents Department

Effect of chordwise vanes on amplitude of tail buffeting

Description: From Summary: "Flight tests have been made with a P-51D airplane to determine the effect of chordwise vanes on the amplitude of tail buffeting. The tests made during abrupt pull-ups to the buffeting boundary included strain measurements on wing and tail and tuft studies over the wing. The results indicate that the vanes tested have no appreciable effect on the amplitude of tail buffeting."
Date: November 10, 1947
Creator: Stokke, Allen R.
Partner: UNT Libraries Government Documents Department

Flight investigation to determine the hinge moments of a beveled-edge aileron on a 45 degree sweptback wing at transonic and low supersonic speeds

Description: Report discussing testing of a model of the pilotless aircraft RM-1 to measure aileron hinge moments in flight in order to determine the reason for loss of roll stabilization at supercritical speeds in flight. The aileron was found to become quickly underbalanced over the full deflection range at supercritical speeds. Information about the general flight behavior, aileron hinge moments, and roll stabilization of the model is provided.
Date: November 12, 1947
Creator: Gardner, William N. & Curfman, Howard J., Jr.
Partner: UNT Libraries Government Documents Department

Free-Spinning-Tunnel Tests of a 1/24-Scale Model of the McDonnell XP-88 Airplane with a VEE Tail

Description: An investigation of the spin and recovery characteristics of a 1/24-scale model of the McDonnell XP-88 airplane has been conducted in the Langley 20-ft free-spinning tunnel. Results of tests with a conventional tail have been previously reported; the results presented herein are for the model with a vee tail installed. The effects of control settings and movements on the erect and inverted spin and recovery characteristics of the model. In the normal loading were determined. Tests of the model in the long-range loading also were made. The investigation included leading-edge-flap, spin-recovery-parachute, and rudder-pedal-force tests. The recovery characteristics of the model were satisfactory for the normal loading. Deflecting the leading-edge flaps improved recoveries. The results indicated that with the external wing tanks installed (long-range loading) recoveries may be poor and, therefore, if a spin is inadvertently entered in this condition the tanks should be jettisoned if recovery does not appear imminent immediately after it is attempted. A 10-foot spin-recovery tail parachute with a towline 40 feet long and a drag coefficient of 0.63 was found to be effective for spin recovery. The rudder pedal force required for spin recovery was indicated to be within the capabilities of the pilot.
Date: November 28, 1947
Creator: Berman, Theodore
Partner: UNT Libraries Government Documents Department

An investigation at low speed of a large-scale triangular wing of aspect ratio two I: characteristics of a wing having a double-wedge airfoil section with maximum thickness at 20-percent chord

Description: Report presenting an investigation of the low-speed characteristics of a 25-foot span triangular wing with an aspect ratio of 2. the airfoil section of the wing was a symmetrical double wedge with 5-percent maximum thickness at 20-percent chord. Results regarding the longitudinal characteristics, lateral characteristics, and directional characteristics are provided.
Date: November 13, 1947
Creator: Anderson, Adrien E.
Partner: UNT Libraries Government Documents Department

Investigation of the Stability and Control Characteristics of a 1/20-Scale Model of the Consolidated Vultee XB-53 Airplane in the Langley Free-Flight Tunnel

Description: An investigation of the low-speed, power-off stability and control characteristics of a 1/20-scale model of the Consolidated Vultee XB-53 airplane has been conducted in the Langley free-flight tunnel. In the investigation it was found that with flaps neutral satisfactory flight behavior at low speeds was obtainable with an increase in height of the vertical tail and with the inboard slats opened. In the flap-down slat-open condition the longitudinal stability was satisfactory, but it was impossible to obtain satisfactory lateral-flight characteristics even with the increase in height of the vertical tail because of the negative effective dihedral, low directional stability, and large-adverse yawing moments of the ailerons.
Date: November 17, 1947
Creator: Bennett, Charles V.
Partner: UNT Libraries Government Documents Department

Low-speed characteristics in pitch of a 42 degree sweptback wing with aspect ratio 3.9 and circular-arc airfoil sections

Description: Report presenting tests in a pressure tunnel to determine the low-speed pitch characteristics of a 42 degree sweptback wing with circular-arc airfoil sections. Information regarding the characteristics of basic wing, leading-edge flap investigation, and effects of fuselage are provided.
Date: November 13, 1947
Creator: Neely, Robert H. & Koven, William
Partner: UNT Libraries Government Documents Department

A Method for Calculating the Heat Required for Windshield Thermal Ice Prevention Based on Extensive Flight Tests in Natural Icing Conditions

Description: An equation is presented for calculating the heat flow required from the surface of an internally heated windshield in order to prevent the formation of ice accretions during flight in specified icing conditions. To ascertain the validity of the equation, comparison is made between calculated values of the heat required and measured values obtained for test windshields in actual flights in icing conditions. The test windshields were internally heated and provided data applicable to two common types of windshield configurations; namely the V-type and the type installed flush with the fuselage contours. These windshields were installed on a twin-engine cargo airplane and the icing flights were conducted over a large area of the United States during the winters of 1945-46 and 1946-47. In addition to the internally heated windshield investigation, some test data were obtained for a windshield ice-prevention system in which heated air was discharged into the windshield boundary layer. The general conclusions resulting from this investigation are as follows: 1) The amount of heat required for the prevention of ice accretions on both flush- and V-type windshields during flight in specified icing conditions can be calculated with a degree of accuracy suitable for design purposes. 2) A heat flow of 2000 to 2500 Btu per hour per square foot is required for complete and continuous protection of a V-type windshield in fight at speeds up to 300 miles per hour in a moderate cumulus icing condition. For the same degree of protection and the same speed range, a value of 1000 Btu per hour per square foot suffices in a moderate stratus icing condition. 3) A heat supply of 1000 Btu per hour per square foot is adequate for a flush windshield located well aft of the fuselage stagnation region, at speeds up to 300 miles per hour, ...
Date: November 1947
Creator: Jones, Alun R.; Holdaway, George H. & Steinmetz, Charles P.
Partner: UNT Libraries Government Documents Department

A method of calculating the compressive strength of Z-stiffened panels that develop local instability

Description: From Summary: "A method, based on the elastic theory for plate buckling and test results for 24S-T aluminum-alloy Z-stiffened panels, is shown for calculating the compressive strength of Z-stiffened panels that develop local instability. This method can be used to calculate the critical compressive stress above, as well as within, the elastic range. For stresses above three-fourths the compressive yield stress the method can be used for the approximate determination of the average compressive stress at maximum load."
Date: November 1947
Creator: Gallaher, George L. & Boughan, Rolla B.
Partner: UNT Libraries Government Documents Department

NACA conference on Aerodynamic Problems of Transonic Airplane Design

Description: Compilation of the papers presented at a NACA conference on transonic airplane design, including stability and control and configurations with extreme sweep. From Introduction: "The purpose of this conference was to convey to those involved in the study of the aerodynamic problems of transonic aircraft these recent research results and to provide those attending an opportunity for discussion of the results."
Date: 1947-11-05/1947-11-06
Partner: UNT Libraries Government Documents Department